Ideas and perspectives: Alleviation of functional limitation by soil organisms is key to climate feedbacks from northern soils
Abstract. Northern soils play an important role in Earth’s climate system as they store large amounts of carbon that, if released, could strongly increase greenhouse gas levels in our atmosphere. Most research to date has focused on how the turnover of organic matter in these soils is regulated by abiotic factors and few studies have considered the potential role of biotic regulation. Here, we claim that soil organisms’ presence or absence is key to understanding and predicting future climate feedbacks from northern soils. We propose that the arrival of soil organisms with currently ‘missing traits’, i.e., properties that the present community does not have, can alleviate functional limitation and result in greatly enhanced decomposition rates, in parity with effects predicted due to increasing temperatures. We base this argument on a series of emerging evidence suggesting that the dispersal of until-then absent micro-, meso- and macro-organisms (i.e., microbes and invertebrate soil fauna) into new regions and newly-thawed soil layers can drastically affect soil functioning. These new observations make us question the current view that neglects organism driven ‘alleviation effects’ when predicting the future feedbacks between northern ecosystems and our planets’ climate. We therefore advocate for an updated framework in which soil biota and their traits become essential when predicting the fate of soil functions in warming northern ecosystems.
Gesche Blume-Werry et al.
Status: final response (author comments only)
RC1: 'Comment on bg-2022-215', Anonymous Referee #1, 12 Dec 2022
- AC1: 'Reply on RC1', Gesche Blume-Werry, 25 Jan 2023
RC2: 'Comment on bg-2022-215', Anonymous Referee #2, 21 Dec 2022
- AC2: 'Reply on RC2', Gesche Blume-Werry, 25 Jan 2023
Gesche Blume-Werry et al.
Gesche Blume-Werry et al.
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This manuscript presents perspective ideas about the future role of soil fauna in northern areas, where permafrost is melting, making large pools of carbon accessible to decomposers. This is obviously an important topic that deserves more attention, efforts so far having been done mostly on the abiotic component of the issue.
Being an important topic, the proposed perspectives have already been presented in the ecological literature and I am afraid that the manuscript only brings little novelty.
For example, a core idea of the MS is that novel traits will bring new ecological functions, but this has been previously proposed (1) and applied to North American boreal regions (2). The fact that soil organisms need to be better integrated in C models has also been highlighted eg (3, 4). Perhaps the most innovative part is the criticism of existing experiments (part 2), but I am not sure that Biogeosciences targets the researchers doing such types of experiments.
The 4th part proposes two simplistic scenarios, overlooking important mechanisms such as vegetation dynamics and its links with soil fauna, competitive exclusion in the context of tradeoffs between competition and colonization and climate change(5) , interactions network rewiring (6) and so on. It also does not separate short term from long term dynamics C and community dynamics, which can be quite different and interact with fires . The possibilities of non linear behaviors with tipping points is also barely mentioned whereas it is a central question (e.g. the provocative compost bomb hypothesis (7)). I think it would be more reasonable to change part 4 and say that we have no real clues about how it will evolve, but mention a number of mechanisms that might play an important role, based on a more thorough literature search beyond soil organisms (for which the manuscript does a good job) and highlight a few key perspectives that need to be explored, at the interface between environment and ecology (= the scope of this journal).
L15 perhaps change “missing traits” with “novel traits” ?
L 18 "micro-organisms”, not “microbes”
L 29 soil property “state”, not “property”
L33 and and the trait matching between decomposers and ressources (eg (8))
L40-44 this has been discussed in (9)
L55 “dispersal” not “dispersion”
L 85 see (2)
L 87 see (10) which show temporal dynamics of worms
L176 “projections” not “predictions”
L185 : competive exclusion may lead to low biodiversity dominated by few species, your point is not obvious.
L195-197 : the point here is the ecological niche (thermal niche), not the distribution (limited by dispersal and ecological niche)
L229 the feedback is barely mentioned in the MS
L251 really close from the figure in (11) perhaps mention it?
Figure 2 : Sorry, I don’t really understand what is the message there.
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